Task: Find the "surplus" word by defining your own reasoning algorithm:
- Oftalmologist
chemistry
The Unicorn
The apple

I: I found several "algorithms" Apple - about the female race, 2. the unicorn, as he is a myth, 3. A chemist - in the other words there is the letter "O" and "4", again a chemist - it begins with an agreed letter... you can probably come up with something else :-) Oh! 5 is Oftalmologist - because I have never touched him before :-D